Professional Reference articles are designed for health professionals to use. They are written by UK doctors and based on research evidence, UK and European Guidelines. You may find the Healthy Eating article more useful, or one of our other health articles.
Treatment of almost all medical conditions has been affected by the COVID-19 pandemic. NICE has issued rapid update guidelines in relation to many of these. This guidance is changing frequently. Please visit https://www.nice.org.uk/covid-19 to see if there is temporary guidance issued by NICE in relation to the management of this condition, which may vary from the information given below.
What is a healthy diet?
A healthy diet should be enjoyable as well as providing a good balance of nutrients. Dietary advice should provide alternatives so that everyone can achieve a diet which is both healthy and enjoyable. The emphasis is on balance and quantity rather than advising complete avoidance of any particular food.
A healthy diet will include moderate amounts of milk and dairy products, meat, fish or meat/milk alternatives, together with limited amounts of foods containing fat or sugar.
- Base meals on starchy foods.
- Eat lots of fruit and vegetables.
- Eat more fish, including a portion of oily fish each week.
- Choose unsaturated oils and use in small amounts.
- Cut down on saturated fat and sugar.
- Eat less salt - no more than 6 g a day.
- Be active and maintain a healthy weight.
- Drink plenty of water.
- Don't skip breakfast.
Government guidance reflects best practice, but is of course only valid at the time of publication. A subsequent study has pointed out that most available data are from European and North American populations where nutrition excess is more likely, so their applicability to other populations is unclear. This prospective cohort study enrolled over 135,000 people aged 35-70 years and without cardiovascular disease, from 18 countries in different geographical regions. Higher carbohydrate intake was associated with an increased risk of total mortality, with those eating the most carbohydrates proportionally having a 28% greater risk than those eating the least, although no difference was seen in the risk of cardiovascular disease or cardiovascular disease mortality. Conversely, intake of total fat and each type of fat was associated with a lower risk of total mortality, while a higher saturated fat intake was associated with lower risk of stroke.
General advice for a healthy diet
The following general advice should be given to patients.
Eat a variety of different foods
No single food provides all the nutrients required for the body to stay healthy.
Eat the right amount to be a healthy weight
Women tend to need less energy than men and older adults tend to need less energy than adolescents and young adults.
Regular aerobic exercise is a very important part of weight control.
Eating breakfast every day can help people control their weight, probably just by decreasing hunger for unhealthy foods later in the day.
Eat starch, fibre and wholegrain foods
Eat plenty of foods rich in starch and fibre - eg, bread, cereals, rice, pasta and potatoes, which also contain fibre, calcium, iron and B vitamins.
Wholegrain foods contain more fibre and other nutrients than white or refined starchy foods and include wholemeal and wholegrain bread, pitta and chapati, wholewheat pasta and brown rice, and wholegrain breakfast cereals.
Wholegrain cereal foods are particularly rich in insoluble fibre, which helps to prevent constipation.
Soluble fibre in fruit, pulses (beans, lentils and chickpeas) and vegetables can help to reduce the amount of cholesterol in the blood.
Increasing fibre reduces the risk of heart disease, diabetes and colorectal cancer.
Eat plenty of fresh fruit and vegetables
There is evidence that a diet rich in fruit and vegetables reduces the risk of developing coronary heart disease and some cancers.
The UK government recommends eating at least five portions of fruit and vegetables daily but in other countries the recommendation is for 7, 8 or even 10. Try to eat a wide variety of different fruits and vegetables.
One portion of fruit or vegetables weighs about 80 g. Some examples are:
- An apple, banana, pear, orange or other similar-sized fruit.
- Two plums or similar-sized fruit.
- A grapefruit or avocado.
- A slice of large fruit, such as melon or pineapple.
- Three heaped tablespoons of vegetables (raw, cooked, frozen or tinned).
- Three heaped tablespoons of fruit salad (fresh or tinned in fruit juice) or stewed fruit.
- A heaped tablespoon of dried fruit (such as raisins and apricots).
- A dessert bowl of salad.
- A glass (150 ml) of fruit juice.
- A cupful of grapes, cherries or berries.
Try to eat at least two portions of fish (fresh, frozen or canned) a week, including a portion of oily fish. This includes oily fish like salmon, mackerel, trout, herring, fresh tuna, sardines, pilchards, and eel. Smoked fish can be high in salt.
With shark, swordfish and marlin, don't have more than one portion a week because of the high levels of mercury.
Protein-rich foods include meat, fish, eggs and pulses.
Poultry such as chicken and turkey contain less fat than meats such as pork and beef, although red meat is a richer source of iron.
Smoked and cured meats should be eaten sparingly. Research indicates they may increase the risk of several types of cancer.
Minerals and vitamins
A healthy diet should contain adequate quantities of all essential vitamins and minerals. A healthy level of most vitamins and minerals will be found in a varied diet rich in fruits and vegetables, protein and dairy products.
Avoid too many foods that contain a lot of fat
Fat contains twice as many calories per gram as carbohydrate or protein so eating a lot of fat will contribute towards obesity.
Foods high in saturated fat include meat pies, sausages, burgers, meat with visible white fat, hard cheese, butter and lard, pastry, cakes and biscuits, chocolate, cream, soured cream and crème fraîche, coconut oil, coconut cream and palm oil.
Avoid frequent sugary foods and drinks
Recommendations suggest that free sugars (found in soft drinks, yoghurts, cakes and biscuits, etc) should not account for more than 5% of total dietary energy.
Sugar causes tooth decay, and sugary foods tend to be high in calories, contributing to obesity
Avoid excessive salt
It contributes to high blood pressure. Government guidelines tailor their advice to children and adults. Children between the ages of 1-18 years should have no more than 2-6 g of salt daily, depending on age. People over the age of 18 should have no more than 6 g of salt a day. Younger children should have even less.
75% of the salt we eat comes from processed food - eg, some breakfast cereals, ready meals, meat products, soups, sauces, bread and biscuits.
Other flavourings can be added to food to make it tasty in place of salt: garlic, herbs or spices.
Ensure adequate fluid intake
In climates such as that of the UK, we should drink approximately 1.2 litres (6 to 8 glasses) of fluid every day to stop us becoming dehydrated. In hotter climates the body needs more than this.
Excessive amounts of caffeine-containing drinks (eg, tea, coffee and cola) should be avoided because of their diuretic effect.
Keep alcohol consumption within recommended limits
Alcohol is also high in calories, so cutting down helps to control weight as well as avoiding other alcohol-related problems. Men and women should not drink more than 14 units of alcohol a week. This should be spread evenly over the week and heavy drinking sessions once or twice a week should be avoided.
A unit is:
- Between a third and a half pint of standard-strength (3-5%) beer, lager or cider.
- A pub measure of spirit.
- A glass of wine - about 2-3 units; alcopops - about 1.5 units.
Alcohol intake should be spread throughout the week. Try to have at least two alcohol-free days each week and avoid binge drinking (more than 6 units for women or 8 units for men).
Further reading and references
Recommendations for Cancer Prevention; World Cancer Research Fund
Your guide to eatwell plate - helping you eat a healthier diet; Public Health England
The Eatwell Guide; Public Health England, 2018
Dehghan M, Mente A, Zhang X, et al; Associations of fats and carbohydrate intake with cardiovascular disease and mortality in 18 countries from five continents (PURE): a prospective cohort study. Lancet. 2017 Aug 28. pii: S0140-6736(17)32252-3. doi: 10.1016/S0140-6736(17)32252-3.
Maintaining a healthy weight and preventing excess weight gain among adults and children; NICE Guidance (March 2015)
Threapleton DE, Greenwood DC, Evans CE, et al; Dietary fibre intake and risk of cardiovascular disease: systematic review and meta-analysis. BMJ. 2013 Dec 19347:f6879. doi: 10.1136/bmj.f6879.
Carbohydrates and Health; Scientific Advisory Committee on Nutrition
Hartley L, Igbinedion E, Holmes J, et al; Increased consumption of fruit and vegetables for the primary prevention of cardiovascular diseases. Cochrane Database Syst Rev. 2013 Jun 46:CD009874. doi: 10.1002/14651858.CD009874.pub2.
van Bussel BC, Henry RM, Schalkwijk CG, et al; Fish consumption in healthy adults is associated with decreased circulating biomarkers of endothelial dysfunction and inflammation during a 6-year follow-up. J Nutr. 2011 Sep141(9):1719-25. doi: 10.3945/jn.111.139733. Epub 2011 Jul 13.
Rong Y, Chen L, Zhu T, et al; Egg consumption and risk of coronary heart disease and stroke: dose-response meta-analysis of prospective cohort studies. BMJ. 2013 Jan 7346:e8539. doi: 10.1136/bmj.e8539.
Zhang X, Lv M, Luo X, et al; Egg consumption and health outcomes: a global evidence mapping based on an overview of systematic reviews. Ann Transl Med. 2020 Nov8(21):1343. doi: 10.21037/atm-20-4243.
De Stefani E, Boffetta P, Ronco AL, et al; Processed meat consumption and risk of cancer: a multisite case-control study in Uruguay. Br J Cancer. 2012 Oct 23107(9):1584-8. doi: 10.1038/bjc.2012.433. Epub 2012 Sep 25.
PHE; Government Dietary Recommendations: Government recommendations for energy and nutrients for males and females aged 1 – 18 years and 19+ years, 2016.
Jequier E, Constant F; Water as an essential nutrient: the physiological basis of hydration. Eur J Clin Nutr. 2010 Feb64(2):115-23. doi: 10.1038/ejcn.2009.111. Epub 2009 Sep 2.
Alcohol Unit Guidelines; Drinkaware